Floating dredge design



Sept. 1, 1964 E. voN BOLHAR FLOATING DREDGE DESIGN 5 Sheets-Sheet 1Filed May 7, 1962 INVENTOR. 06741? l/OA/ 504/744 Sept. 1, 1964 E. VONBOLHAR 3,146,537

FLOATING DREDGE DESIGN Filed May 7, 1962 5 Sheets-Sheet 2 p 1964 E. VONBOLHAR FLOATING DREDGE DESIGN 5 Sheets-Sheet 3 Filed May 7, 1962 M a e a5 KW w E W me my I V p W m j V a Qx M Sept. 1, 1964 E. VON BOLHAR mommaDREDGE DESIGN 5 Sheets-Sheet 4 Filed May 7, 1962 INVENTOR. E0674? l/OA/504/144 Sept. 1, 1964 E. VON BOLHAR FLOATING DREDGE DESIGN 5Sheets-Sheet 5 Filed May 7, 1962 INVENTOR.

F/K/v EX LQVEA/ 5 21 United States Patent 3,146,537 FLOATING DREDGEDEEaiGN Edgar von Boihar, Severna Park, Md, assignor to Ellicott MachineCorporation, Baitirnore, Md, a corporation of Maryland Fiied May 7,1962, Ser. No. 192,860 (Jiaiins. (Cl. 37-69) This invention relatesgenerally to dredges and more particularly to a novel and improved,high-capacity dredge for excavating and grading the bottoms of rivers,lakes, harbors and the like.

The commercial success of the dredge hinges to a great extent upon twoprime factors; the cost of dredging a given volume of material, and theaccuracy with which the dredge maintains the depth of dredging. Thefirst factor, the cost of dredging, of course, determines the dredgeowners expense and therefore, should be as low as possible. The secondfactor, the accuracy of dredging, however, is also critical since it iscustomary to price a particular dredging operation on the basis of theamount of material which must be excavated or dredged to obtain adesignated depth. If the operator dredges to a depth beyond thatrequired, he receives little or no compensation for the excessivedredging.

The maintenance of depth accuracy has in the past depended to a greatextent upon the skill of the operator in judging an operation which hecannot observe under muddy waters present during dredging operations.

A dredge incorporating this invention operates economically since thedredging is continuous and the material dredged is carried to thedesired location without double handling or the use of separate handlingequipment. An endless bucket chain performs the dredging and by virtueof its continuous operation, the dredging capacity is high. Such abucket chain operates with substantially uniform power requirements sothat the power equipment for driving the chain is substantiallyuniformly loaded. This promotes operating economy. Continuouslyoperating conveyor means also are provided to transport the materialdredged by the bucket chain to the desired location for deposit. Hereagain, continuous operation of conveying also lends to operating economysince the operating power load is substan tially uniform.

The accuracy of dredging depth control is achieved by providing asubmerged ladder with positive guide tracks to accurately position thebuckets during the dredging operation in combination with support meansfor the submerged ladder which enables the operator to accuratelyposition the ladder.

Since the dredge incorporating this invention economically operates toperform the dredging operation and since the dredge is arranged topermit the operator to accurately control the depth and grade ofdredging, a commercially superior dredge results.

It is an important object of the invention to provide a novel andimproved dredge which efficiently operates to accurately excavate andgrade sub-aqueous material.

It is another important object of this invention to provide a novel andimproved dredge operable to continu ously excavate, grade and transportthe excavated material at locations remote from the dredge to eliminatedouble handling of the excavated material.

It is still another object of this invention to provide a novel andimproved dredge operable to economically excavate large amounts ofsub-aqueous material while maintaining accuracy of depth and grade.

It is still another object of this invention to provide a dredge havingnovel and improved means to enable the operator to accurately determinethe depth and grade of a sub-aqueous excavating operation.

It is still another object of this invention to provide a novel andimproved integrated dredge combining a bucket chain to excavate andgrade sub-aqueous material with a system of transportation fortransporting and depositing the excavated material, thereby minimize therequirement of separate handling equipment.

Other objects and advantages will appear from the following descriptionand drawings, wherein FIGURE 1 is a perspective View of a dredgeincorporating this invention;

FIGURE 2 is a side elevation illustrating the general structure of thebucket chain and support mechanism therefor;

FIGURE 3 is a section taken along 3-3 of FIGURE 2;

FIGURE 40 and FIGURE 4b are comparative views, in side elevation,illustrating the operation of the dredge in grading and excavating acontinuous slope;

FIGURE 5 is a schematic view of the indicators for informing theoperator of the position and depth of the lower ladder;

FIGURE 5a is an enlarged fragmentary view of the depth indicator;

FIGURE 6 is a fragmentary perspective view of a second form of thisinvention, wherein a hydraulic pump and pipe line is used to transportand discharge the excavated material;

FIGURE 7a is a plan view of one preferred arrangement for controllingthe position and movement of the dredge during a dredging operation;

FIGURE 7b is an end view illustrating the anchor line arrangement forthe anchor barges; and

FIGURE 76 is a side elevation illustrating the cable arrangement forcontrolling the position of the dredge.

The machinery of the dredge is mounted on a barge type hull It An upperor articulated ladder 11 is pivoted at 12 on a rigid support 13 mountedon the deck of the hull 10. A forward winch mast 14 is mounted at theforward end of the hull lit and is provided with cable sheaves 16 overwhich forward winch cables 17 extend. The forward winch cables 17connect to a yoke 18 pivotally connected at 23 to the forward end of theupper ladder 11 for raising and lowering of the ladder causing it topivot around its pivot 12. Suitable forward winch drums 19 and forwardwinch drives 21 operate the cables 17.

A lower ladder 22 is pivoted at 23 to the upper ladder 11 and extendsback along the dredge as best illustrated in FIGURE 2. A second winchmast 24 is mounted on the hull it above the rearward end of the lowerladder 22 and is again provided with cable sheaves 2d and winch cables27 which connect to a yoke 28 mounted at the rearward end of the lowerladder 22. Here again, suitable cable drum 29 and power drive 31 areconnected to the cables 27 and operated to raise and lower the rearwardend of the lower ladder 22. Thus, the lower ladder 22 can be raised orlowered by the proper operation of the two winch drives 21 and 31. Theforward winch determines the depth of the forward end of the ladder 22and the rearward winch determines the depth of the rearward end of thelower ladder. The upper ladder 11 serves as a rigid articulated supportwhich, in cooperation with the two winches, accurately positions thelower ladder.

A pair of continuous parallel chains 32 carry buckets 33 around the twoladders 11 and 22. The chains 32 are provided with rollers 49 which movealong tracks 37 (illustrated in FIGURE 3) on the lower ladder 22 aroundthe idler sprocket 38 at the forward end of the lower ladder and upalong tracks 39 on the upper ladder 11, to drive sprockets 34illustrated in FIGURE 2. From the sprockets 34 the chains extend aroundtension- 3 ing idlers 41 to idler sprockets 42 pivoted at the rearwardend of the lower ladder 22. Additional idlers 43 are mounted on theupper side of the lower ladder 22 to engage the chains 32 when the lowerladder is raised near the surface.

The drive sprockets are mounted on and driven by a drive shaft 36 whichis powered by a suitable engine drive (not shown) in the machinery house59. In the illustrated embodiment the drive shaft also serves as thepivot shaft of the pivot 12.

Buckets 33 are mounted between the chains and are carried thereby aroundthe two ladders 11 and 22. These buckets 33 are constructed so that theyexcavate the subaqueous material as they move along the lower ladder 22and carry the excavated material up along the upper ladder. They areinverted as they pass by the drive sprockets 34 and empty onto a chute50.

The tensioning idlers 41 are supported on bearing blocks 44 which slidealong tracks 46 on the deck of the hull 10 and are pressed forward byfluid pressure operated actuator 47 to maintain the proper tension onthe chains 32. As the two ladders 11 and 22 are lowered, it is necessaryfor the tension idlers 41 to move back along the hull 10 against theforce of the actuators 47. Conversely, when the ladders are raised, itis necessary for the idlers 41 to move forward under the influence ofthe actuators 47 to maintain the proper tension in the chains 32. Theactuators 47 are preferably of the piston and cylinder type maintainedat a fluid pressure which will produce a forward force on the idlers 41of the required magnitude to maintain the proper tension in the chains32.

Referring again to FIGURE 3, rollers 49 are mounted on the chains 32 atequally spaced points along the chains to support the chains in thevarious tracks and to engage the drive sprockets 34 for driving thechains on the ladders. These rollers and tracks operate to accuratelyposition the chains 32 and in turn, the buckets 33 as they move. Theupper ladder 11 is provided with a plate 4-8 immediately adjacent to thebuckets 33 along which the buckets move to prevent the excavatedmaterial from dropping down out of the buckets until they reach the areaof the sprockets 34. The chute 50 on the support 13 receives theexcavated material and carries it to a belt conveyor 51, driven totransport the excavated material to the stern of the hull 10. Fromthere, the conveyor drops the material onto a series of conveyors, thefirst of which is illustrated at 52. The conveyors carry the excavatedmaterial to the desired location for deposit. Generally, the conveyors52 are of the shaker-type which are supported on floats 53 in the usualmanner. A stern mast 55 is provided to support the conveyor winch cables54. Here again, a power driven winch drum 56 having a drive 57 is usedto power the conveyor winch.

The hull 10 is generally U-shape, having a central longitudinallyextending well 58 through which the ladders and chains extend. The lowerladder 22 may be raised to a position within the well 58 wherein thebuckets 33 extending along the lower side of the ladder are above thebottom of the hull so that the dredge can be moved through relativelyshallow water.

The machinery house 59 is provided on one side of the hull 10 to housethe various power drives and to provide the necessary crew facilities.The controls for all of the winches and various other power accessoriesare located in a control house 61 above the machinery house 59.

In order to provide the operator with an exact indication of theposition of the lower ladder 22, an indicator system illustratedschematically in FIGURES and 5a is used. Various elements have beenremoved for simplification and the relative sizes of the indicatorelements are exaggerated.

In order to determine the depth of the forward end of the ladder 22, adepth indicator 62 is provided. The depth indicator 62 includes avertically movable arm 63 restrained to move vertically by a collar 64slidable on a rod 66 which is in turn mounted on the support 13. Asecond arm 67 extends from the rearward side of the collar 64 through asleeve 68 pivoted on the upper ladder 11. As the ladder 11 rotates aboutits pivot 12, the pivot 63 moves up and down carrying with it the arm67. During such movement the sleeve slides horizontally along the arm67. Therefore, the vertical position of the arm 63 is determined by thevertical position of the pivoted sleeve 68, which is in turn determinedsolely by the position of the upper ladder 11. Since the upper ladder 11is rigid, the position of the arm 63 is directly related to the verticalposition of the pivot 23 at the lower end of the ladder llll. Since thelower ladder is connected at the pivot 23, the height of the bucketsmoving along the lower ladder 22 immediately below the pivot 23 istherefore directly related to the vertical position of the arms 63 and67. A scale 69 is calibrated in depth of the buckets 33 immediatelybelow the pivot 23 and permits the operator to see at a glance theirexact depth.

In order to determine the angle of the lower ladder 22 the slopeindicator informs the operator of the exact slope of the ladder and withthe depth information of the indicator 62, informs the operator of theexact position and depth of the lower ladder 22. To provide the slopeindication, a parallelogram structure is used. A slope indicator arm 71is pivoted on the support 13 for rotation about the axis of the pivot 12and is formed with an arm 72 pivoted at 73 to a rod 74. The lower end ofthe rod 74 is pivoted at '76 to the lower ladder 22. The rod 74 has alength equal to the spacing in between the pivots 12 and 23 and thedistance between the pivots 23 and 76 is equal to the distance betweenthe pivots 12 and 73. Therefore, a parallelogram is provided whichincludes the upper ladder 11, the indicator arm 72, the portion of thelower ladder between the pivot 23 and 76, and the rod 74. The indicator71 is, therefore, always positioned with its arm 72 parallel to the linebetween the two pivots 23 and 76. The indicator 71 is provided with apointer 77 which in cooperation with a scale 73 on the support 13indicates the angle of the lower ladder 22. It should be recognized thatthe depth and angle indicators are schematically illustrated and thatother forms of indicating mechanisms may be provided. In addition,remote read-out equipment can be located in the control house 61convenient to the operator of the dredge.

Since the two indicators provide a continuous indication of the depthand angle of the lower ladder, the operator is able to control the twowinch drives 21 and 31 to accurately position the lower ladder 22 and inturn, accurately excavate to the desired depth and grade even though theoperation is performed under muddy waters, stirred up by the excavationprocess.

Reference should now be made to FIGURES 4a and 4b which illustrate theoperation of the dredge in establishing a grade for river bankrevetments and the like. The river bottom before excavation and dredgingis indicated by the broken line 81 and after dredging by the grade line82. In FIGURE 4b, the dredge is shown as it moves toward shore, dredgingthe river bottom to the desired grade. The buckets 33 are carried by thechains 32 along the lower ladder 22 to continuously remove material asthe dredge is moved forward. The material in the buckets 33 is carriedup along the upper ladder 11 and is deposited on the chute 50 andcarried to the desired location of the deposit by the conveyors 51 and52.

As the dredge moves forward, the forward winch drum 19 is operated toraise the upper ladder 11 to adjust the depth of the forward portion ofthe lower ladder 22 and the rearward winch drum 29 is operated tomaintaian the required angle of the lower ladder 22. Therefore, theladder 22 is accurately positioned and the grade is accuratelydetermined. If there are any holes in the river bottom as indicated at85 which extend below the grade level required, the action of thebuckets 33 will cause the holes to be filled and produce a smooth grade.

As the dredge continues to excavate the bottom, it is moved toward shoreto the position illustrated in FIG- URE 40. During the forward movementof the dredge, the winch drums l9 and 29 are operated to maintain therequired position of the lower ladder 22. A comparison of FIGURES 4a and4b will illustrate that as the dredge is moved toward shore, the forwardend of the lower ladder 22 is raised by raising the upper ladder 11 to amore nearly hoiizontal position and the angle of the lower ladder 22 ismaintained by properly operating the winch connected to the rearward endof the ladder. The actuators 47 extend as the lower ladder is raised tomaintain the proper tension in the chains 32.

The dirt removed from the bottom is carried contintously by the endlesschain of buckets 33 to the conveyors 51 and 52 to a location where it isdeposited. In many cases, the material is dropped in the center of thestream where the current carries it away. In other cases, the conveyorsare arranged to carry the material to the shore to build up the bank.

In FIGURE 6, a second embodiment of the invention is illustrated whereinthe transportation of the material excavated is performed by a hydraulicpump and pipe line. In this embodiment, the chute 89 carries thematerial laterally to a sump 83 formed in the hull it and provided withopenings which 'allow water to enter the sump 33 and mix with thematerial. The mixture of water and excavated material is then pumpedthrough an intake pipe 84 to a hydraulic pump 86 and dischargedtherefrom through a pipe line d7. A suitable engine 38 is used to drivethe pump. This equipment method of hydraulic transportation of thematerial has the advantage when the material is to be carried aconsiderable distance before being deposited and is normally used whenthe material is to be deposited either on the river bank or in locationssubstantial distances from the dredge. The operation of the continuousbucket chain however, is identical in both embodiments.

Reference should now be made to FIGURES {7a through 70 which illustrateone apparatus for accurately controlling the position and movement ofthe dredge itself. The dredge hull it) is suspended or supported betweentwo anchor barges 91 and 92. The anchor barges 91 and 92 are positionedwith the barge 91 upstream from the dredge and the barge d2 downstreamtherefrom. Anchor lines 3 extend to ofishore anchors and coperate withonshore anchor lines 94 to accurately locate the barges in position.Power winches 96 on the barges control the anchor lines 93 and 94.

The dredge is connected by bow lines 97 and parallel stern lines 98 tothe two barges 91 and 92. When the upstream lines 97 and 98 are takenin, while letting out the downstream lines, the dredge is moved upstreamtoward the barge 91. Conversely, when the downstream lines are taken inwhile letting out the upstream lines, the dredge moves downstream towardthe barge 92. A pair of lines 99 and 191 are used to move the dredgetoward shore during the dredging operations. The line 99 connects thestern of the hull it) to the forward or shore end of the barge 91 andsimilarly the line lit-1 connects the stern of the hull it to theforward end of the barge 92. As the two lines 99 and ltil are taken in,the dredge hull ltl is moved forward toward the shore against thereaction thrust produced by the buckets.

The lower end of the ladder is laterally supported by lines 1G2 and 193illustrated in FIGURE 70. Since the lower ladder 22 and the upper ladder111 are subjected to the flow forces of the stream, the lower support ofthe lines 102 and 1103 often are required.

When a dredge incorporating this invention is used in the dredging ofharbors or channels, the rigging for moving the dredge and locating itcan be changed to meet the needs of the particular operation.

Because the dredge incorporating this invention accurately maintains thedesired depth and grade angle of dredging and operates to continuouslyremove material from the bottom, it is economical to operate, provideshigh dredging capacity. Because the depth and grade can be accuratelymaintained, time and effort is not wasted in overdredging, yet therequired minimums are achieved. The action of the dredge in fillingholes which may be encountered also improves the overall resultsachieved since the material used to fill the holes need not be carriedaway from the site. Since the grade resulting is smooth, the cementmattress which is laid during the construction of the revetment layssmoothly along the bottom of the river.

Although preferred embodiments of this invention are illustrated, it isto be understood that various modifications and rearrangements of partsmay be resorted to without departing from the scope of the invention asdefined in the following claims.

What is claimed is:

1. A dredge comprising a hull, an upper ladder, a first pivot connectingone end of said upper ladder to said hull, a lower ladder, a secondpivot connecting one end of said lower ladder to the opposite end ofsaid upper ladder, hoist means operable to control the depth and angleof said lower ladder relative to said hull, a first indicator, aconnection between said upper ladder at a point spaced from said firstpivot and said first indicator moving said first indicator verticallyrelative to said hull as said upper ladder pivots relative thereto, asecond indicator on said hull, operating means connecting said lowerladder and said second indicator maintaining a fixed relationshipbetween the position of said second indicator relative to said hull andthe angle of said lower ladder, a power driven endless bucket chain, andmeans guiding said chain along said lower ladder for dredging and upalong said upper ladder to said hull to carry dredged material to saidhull.

2. A dredge comprising a hull, an upper ladder, a first pivot connectingone end of said upper ladder to said hull, a lower ladder, a secondpivot connecting one end of said lower ladder to the opposite end ofsaid upper ladder, hoist means operable to control the depth and angleof said lower ladder relative to said hull, first indicator means, aconnection between said upper ladder at a point spaced from said firstpivot and said first indicator means moving said first indicator meansrelative to said hull as said upper ladder pivots relative thereto,second indicator means piv oted on said hull, operating means connectedbetween said lower ladder and said second indicator means rotating thelatter in fixed relationship to the angle of said lower ladder relativeto said hull, a power driven endless bucket chain, means guiding saidchain along said lower ladder for dredging and up along said upperladder to said hull to carry dredged material to said hull, and conveyormeans operable to receive said dredged material from said bucket chainsand carry it to a location for deposit.

3. A dredge comprising a hull, an upper ladder, a first pivot connectingone end of said upper ladder to said hull, a lower ladder, a secondpivot connecting one end of said lower ladder to the opposite end ofsaid upper ladder, hoist means operable to control the depth and angleof said lower ladder relative to said hull, a first indicator mounted tomove vertically on said hull, a connection between said upper ladder ata point spaced from said first pivot and said first indicator movingsaid first indicator vertically relative to said hull as said upperladder pivots relative thereto, a second indicator pivoted on said hullco-axial with said first pivot, an operating rod pivoted to shid lowerladder and said second indicator and in cooperation with said upperladder forming a parallelogram, a power driven endless bucket chain,means guiding said chain along said lower ladder for dredging and upalong said upper ladder to said hull to carry dredged material to saidhull, and conveyor means operable to receive said dredged material fromsaid bucket chains and carry it to a location for deposit.

4. A dredge comprising a hull, a unitary upper ladder pivoted at one endon said hull, a unitary lower ladder pivoted at one end thereof to theother end of said upper ladder, hoist means connected to adjust thevertical and angular position of said lower ladder relative to saidhull, guide means on said ladders, an endless bucket chain movable insaid guide means along both of said ladders and having a portionextending free of said guide means between said one end of said upperladder and the other end of said lower ladder, tension wheels movablealong said hull engaging said portion of said chain with a forceproviding a minimum tension therein, and a power drive connected to saidchain at said one end of said upper ladder operable to pull said chainfrom said other end of said lower ladder to said other end of said upperladder and therealong to said one end of said upper ladder.

5. A dredge comprising a hull, a unitary upper ladder pivoted at one endon said hull, a unitary lower ladder pivoted at one end thereof to theother end of said upper ladder, hoist means connected to adjust thevertical and angular position of said lower ladder relative to saidhull, guide means on said ladders, an endless bucket chain movable insaid guide means along both of said ladders and having a portionextending free of said guide means between said one end of said upperladder and the other end of said lower ladder, tension wheels movablealong said hull engaging said portion of said chain, force meanspressing said tension wheels against said chain with a force providing aminimum tension therein, and a power drive connected to said chain atsaid one end of said upper ladder operable to pull said chain from saidother end of said lower ladder to said other end of said upper ladderand therealong to said one end of said upper ladder.

References Cited in the file of this patent UNITED STATES PATENTS 8,840Hamilton Mar. 30, 1852 268,977 Angell Dec. 12, 1882 484,763 Bowers Oct.18, 1892 503,655 Ellicott Aug. 22, 1893 510,736 Urie Dec. 12, 1893530,675 Ball Dec. 11, 1894 1,126,306 Sheppard Jan. 26, 1915 2,147,062Rosener Feb. 14, 1939 2,178,265 Peterson Oct. 31, 1939 FOREIGN PATENTS352,997 Great Britain Aug. 30, 1905 659,845 Great Britain Oct. 31, 1951457,364 Germany Apr. 1, 1926 265,120 taly Nov. 3, 1928

1. A DREDGE COMPRISING A HULL, AN UPPER LADDER, A FIRST PIVOT CONNECTINGONE END OF SAID UPPER LADDER TO SAID HULL, A LOWER LADDER, A SECONDPIVOT CONNECTING ONE END OF SAID LOWER LADDER TO THE OPPOSITE END OFSAID UPPER LADDER, HOIST MEANS OPERABLE TO CONTROL THE DEPTH AND ANGLEOF SAID LOWER LADDER RELATIVE TO SAID HULL, A FIRST INDICATOR, ACONNECTION BETWEEN SAID UPPER LADDER AT A POINT SPACED FROM SAID FIRSTPIVOT AND SAID FIRST INDICATOR MOVING SAID FIRST INDICATOR VERTICALLYRELATIVE TO SAID HULL AS SAID UPPER LADDER PIVOTS RELATIVE THERETO, ASECOND INDICATOR ON SAID HULL, OPERATING MEANS CONNECTING SAID LOWERLADDER AND SAID SECOND INDICATOR MAINTAINING A FIXED RELATIONSHIPBETWEEN THE POSITION OF SAID SECOND INDICATOR RELATIVE TO SAID HULL ANDTHE ANGLE OF SAID LOWER LADDER, A POWER DRIVEN ENDLESS BUCKET CHAIN, ANDMEANS GUIDING SAID CHAIN ALONG SAID LOWER LADDER FOR DREDGING AND UPALONG SAID UPPER LADDER TO SAID HULL TO CARRY DREDGED MATERIAL TO SAIDHULL.